閱讀障礙者之視知覺能力探討

The Visual-Perceptual Abilities of Chinese Dyslexic Children

視知覺若以傳導路徑之功能來論，分成何物路徑及何處路徑兩條路徑，分別進行物體辨識及空間定位的處理。目前並沒有以雙視覺腦皮質處理路徑為理論依據來探討閱讀障礙者表現之研究，因而本研究企圖依雙視覺－腦皮質路徑的特性，設計作業分別探討閱讀者處理物體辨識及空間定位的能力，間接驗證巨細胞缺陷理論。共有18名閱讀障礙生及24名一般生參加本研究自行設計的九宮格作業，參與者被要求必須快速判斷呈現在電腦螢幕上的字母是什麼或它在九宮格的那個位置，結果發現閱讀障礙者的反應時間顯著慢於一般兒童，然而正確率則沒有顯著差異。因此，閱讀障礙組的物體辨識及空間定位能力可能都較普通人差。同時，本研究的發現也間接指出巨細胞缺損假說可能不獲支持。

There are two visual-processing streams, the what and where pathways, that served different functions. The what pathway is responsible for determining an object's identity, and the where pathway is responsible for determining object’s location. So far there is little research on the where and what pathways and dyslexia. The purpose of this paper was to design a nine-cell task, that could discriminate the functions of the what and where pathways, and to explore the visual-perceptual functions of dyslexia. There were 18 dyslexic and 24 normal students participated this task. They were asked to answer which one cell the letter on is or what the letter is. Our result shows that the reaction time of dyslexic students is lower than the normal, but there’s not significantly different in accuracy. The conclusion is that dyslexic students have the visual-perceptual defect, and it's not consistent with the hypothesis of the magnocellular theory of dyslexic students.